7 Series B Companies Worth Prospecting in 2026

A Series B company has already demonstrated enough traction to fund expansion, but funding alone doesn’t prove agency fit. The U.S. market has usually produced 600 to 900 Series B rounds annually, outside the 2021–22 peak, and Series B typically represents one out of every six or seven venture dollars, according to Crunchbase’s Series B analysis. That makes the round a useful prospecting signal, not a ready-made lead list.

The seven examples below span infrastructure, vertical SaaS, financial technology, regulated security, research technology, and legal AI. The evaluation lens is practical: technical complexity, visible product expansion, compliance or integration burden, likely agency entry point, and account priority. This is for founders and CEOs of 100–500-person software development agencies building niche authority and qualified pipeline, not founders researching venture funding.

1. NetBox Labs

NetBox Labs is a strong infrastructure prospect because its product sits between open-source adoption and enterprise operational control. It commercializes NetBox, an open-source network source of truth, through NetBox Cloud and Enterprise editions. Its product surface includes deployment, security, SSO, plugins, NetBox Discovery, NetBox Assurance, Copilot, and Nitro AI initiatives.

The technical complexity is high, but the buying friction isn’t limited to engineering. NetBox Labs must help customers replace or connect with internal CMDB and IT asset management systems, eliminate configuration drift, and support security, high availability, and compliance requirements. That creates agency opportunities in integrations, enterprise implementation, migration tooling, developer experience, and documentation that helps technical evaluators reach a buying decision.

Its July 2025 Series B was $35 million, giving the account a visible expansion signal. The product direction toward automation and AI for datacenter infrastructure also creates a narrower authority lane than generic cloud consulting.

What an agency should sell

Don’t lead with “we build SaaS platforms.” Lead with the operational problem:

• Infrastructure integration: Connect NetBox with the systems enterprise teams already use.
• Automation delivery: Build workflows around Discovery, Assurance, and certified plugins.
• Enterprise adoption: Improve onboarding, deployment guidance, SSO flows, and technical documentation.
• AI infrastructure trust: Help make infrastructure data usable for Copilot and Nitro AI initiatives.

The open-source community may create bottom-up adoption, but the sales-led pricing model can slow smaller evaluations. An agency should therefore target product, platform, and enterprise engineering leaders, not broad marketing contacts.

Positioning decision: Own “enterprise NetBox implementation and automation” rather than competing for the vague category of cloud development.

Priority: Specialist. Prospect when NetBox Labs announces integrations, enterprise partnerships, security releases, or expansion of its plugin ecosystem. The best first asset is a technical teardown showing how a network source of truth connects to existing operational systems.

2. Method Financial

Method Financial is a high-complexity prospect because its API work reaches regulated money movement. The platform connects financial liabilities, retrieves balances and terms, and supports direct debt payments or balance transfers through its Connect, Data, and Pay products. That combination places integration reliability and customer workflow design in the same buying conversation.

The company raised a $42 million Series B in January 2025, a clear expansion signal. It does not remove the implementation friction facing financial institutions and fintech platforms. Buyers still need to assess authentication, transaction confirmation, compliance workflows, integration reliability, and the user experience before approving production use.

The agency opportunity sits between API infrastructure and the end-user financial journey. Liability matching can reduce manual entry, while payoff and transfer workflows can reduce user steps. Method’s Postman resources and API documentation support trials and proof-of-concept work, yet production deployment requires deliberate architecture, testing, and operational handoff.

A useful account thesis is regulated product delivery. An agency should show how it would:

• Design integration architecture: Map Method’s APIs into lending, personal finance, debt management, or banking products.
• Prepare compliance evidence: Create implementation patterns, audit trails, and handoff documentation for regulated review.
• Improve financial workflows: Refine enrollment, payoff, and balance-transfer interfaces without making unsupported performance claims.
• Shorten proof-of-concept work: Build a controlled demonstration using the available API and Postman materials.

The outreach decision follows from the technical risk. Use a go to market engine only after defining the regulated use case, buyer, and integration boundary. A broad fintech-development offer will create little urgency; an architecture note tied to liability connectivity, payment confirmation, or compliance handoff gives product and engineering leaders a reason to respond.

Priority: High-complexity. Monitor publicly verified signals such as new creditor coverage, partner announcements, API releases, hiring, and expansion. Target product and engineering leaders with a concise integration assessment, not general marketing contacts. The agency earns authority by reducing uncertainty between an API trial and a regulated production rollout.

3. Hypori

Hypori is a high-complexity security account. Its platform provides zero-trust mobile access by isolating enterprise applications and data from personal devices. Hypori Mobile, Secure Messaging, and Lyte for Apps serve government, defense industrial base, and financial services environments, where deployment controls and evidence can influence the buying process as much as product capability.

Hypori completed a $12 million Series B extension in January 2025. Its SOC 2 Type 2 posture, deployments with U.S. Air Force units, and FedRAMP authorization listed as “In Process” at High impact provide validation for regulated buyers. They also narrow the credible agency pool. Any prospective partner must be able to discuss security architecture, device policy, documentation, and procurement workflows without making certification claims it cannot support.

The account’s buying friction is operational. Public-sector procurement, security review, device requirements, and customer deployment work can extend the path from evaluation to revenue. An agency should therefore sell a defined implementation capability, not a broad mobile-development package.

A useful positioning thesis is controlled-environment delivery:

• Secure mobile integration: Connect enterprise applications to Hypori’s virtual workspace while preserving the isolation model.
• Deployment enablement: Build configuration tools, administrator workflows, and technical guidance for government and defense customers.
• Compliance documentation: Organize evidence collection and customer-facing implementation materials, while leaving formal certification to qualified parties.
• Partner delivery: Serve as the engineering team for integrators that already sell into regulated accounts.

Hypori’s BYOD privacy proposition gives outreach a clear technical subject, but its addressable audience is narrow. Consumer mobile experience work and generic app modernization are poor entry points. The stronger play is a security-aware implementation assessment tied to one deployment environment, with a proof asset showing how the agency works inside controlled systems.

Priority: High-complexity. Monitor government, defense, financial services, and compliance-related product announcements, along with hiring or partner signals. Target product, security, and engineering leaders. The agency earns a response by reducing deployment uncertainty, not by presenting another general capability deck.

4. Spellbook

Spellbook is the roster’s clearest product-led prospect. Its legal AI platform handles contract drafting, review, comparison, and question-answering through Microsoft Word integrations, playbooks, clause libraries, and preference learning. The roadmap also includes Autonomous Contract Management and continuing enterprise security updates.

The company reported a $50 million Series B in late 2025 or early 2026 and serves more than 4,500 legal teams, according to the supplied company details. A 7-day free trial gives prospects a direct evaluation route, unlike the procurement-heavy motions associated with Hypori and Method Financial.

That route creates a visible buying funnel for agency work. The first opportunity is product engineering that reduces friction between trial use, team adoption, and enterprise rollout. The second is evidence-led content addressing accuracy, governance, data handling, and fit with legal workflows.

Spellbook’s feature set also signals technical complexity. “Compare to Market” and preference learning place AI inside document processes where traceability and contract risk affect trust. The agency must therefore show it can improve the workflow around the model, not add another conversational interface.

A focused offer could cover:

• Microsoft Word workflow engineering: Improve the transition between legal drafting and AI-assisted review.
• Enterprise controls: Build administration, permissions, audit, and configuration experiences.
• Evaluation design: Shape the path from free trial to controlled team deployment.
• AI visibility content: Explain how the product fits legal operations and enterprise review. Teams can use AI visibility guides to sharpen that authority position.

Targeting decision: Treat Spellbook as a fast-moving product account. Monitor feature releases, security announcements, Microsoft ecosystem activity, and new enterprise workflows. Contact product, engineering, and demand leaders with a teardown of the trial, Word experience, or transition into contract management. The strongest positioning is specialist support for legal AI adoption, where model behavior, workflow design, and buyer confidence must work together.

5. Aiera

Aiera is a specialist financial-data prospect with a technical wedge that makes account selection straightforward. Its platform handles live financial events, sub-second transcription, AI summaries, topic extraction, alerts, and an “Ask Aiera” chatbot. Mobile apps, embeddable components, and SDKs extend the product across research environments rather than confining it to one interface.

Aiera closed a $25 million Series B in June 2025. Its focus on earnings calls, conferences, investor-relations events, equities, and research workflows limits the market, but that focus creates a useful qualification signal. An agency with capital-markets data experience can establish relevance quickly. A generalist agency will need stronger proof before earning attention.

The account’s technical complexity is high: real-time media, transcription, search, summarization, permissions, and embedded delivery must work together. Researchers want rapid answers during live events, while financial institutions add security, procurement, and integration requirements. Those constraints create buying friction, so a broad capabilities pitch is unlikely to help.

Aiera offers several possible entry points, but outreach should choose one. Embedded research workflows are a stronger opening than a catalogue of services because they connect a specific product surface to an identifiable user problem.

A focused agency offer could include:

• Research workflow integration: Place Aiera components inside analyst workspaces and internal research tools.
• Event intelligence interfaces: Improve alerts, topic navigation, summaries, and question-answering flows.
• Data-product architecture: Support ingestion, transcription, indexing, and retrieval workflows.
• Enterprise rollout: Prepare technical enablement for financial institutions and investor-relations teams.

Targeting decision: Classify Aiera as a specialist account with high technical complexity and selective buying friction. Monitor SDK releases, mobile capabilities, event coverage announcements, and financial-institution partnerships. Contact product or engineering leadership with one integration thesis, supported by a concise example of a financial research workflow the agency could improve. The positioning should emphasize capital-markets product fluency, not generic AI delivery.

6. Outset

Outset sells a research technology platform built around AI-moderated interviews and customer experience management. Its agents probe dynamically, synthesize themes, extract quotes, and create highlight reels. The product supports more than 40 languages and can run more than 50 concurrent interviews, according to the supplied product details.

Outset announced a $30 million Series B on December 10, 2025 and lists Microsoft, Nestlé, HubSpot, Uber, Away, and Glassdoor among its enterprise customers. These logos indicate credibility, while also pointing to the account’s main buying friction: research and CX teams must adapt established survey, interview, and feedback processes.

The technical challenge is adoption across several roles. Participants need a simple interview experience. Researchers need control over guides, recruitment, languages, and analysis. Executives need findings they can use, rather than another dashboard. Multimodal research therefore creates product, workflow, and governance requirements at the same time.

Position the agency around adoption

The strongest agency play is product expansion tied to enterprise rollout. A partner could improve the operational path from research design to decision-ready output:

• Research workflow design: Refine guide setup, participant management, analysis, and share-outs.
• Enterprise controls: Add permissions, workspace governance, and review workflows.
• Multilingual experience: Improve researcher and participant journeys across the product’s language capabilities.
• Activation content: Convert research workflows into technical education that helps buyers understand the operational change.

Targeting decision: Treat Outset as a fast-moving product account with enterprise-content potential and meaningful workflow complexity. Monitor new research formats, CX integrations, enterprise controls, and customer expansion signals. Open with a workflow audit rather than a general development pitch or case-study request.

Outreach angle: Position the agency around fewer handoffs between research design, participant interviews, synthesis, and executive share-outs.

7. Topline Pro

Topline Pro is the group’s most clearly defined vertical account. Its AI operating system serves U.S. home-services SMBs through website and SEO tools, social automation, reviews, inbound lead handling, quoting, invoicing, and payments. Sidekick AI extends into call answering, speed-to-lead, quoting, and other marketing, sales, and operational tasks.

Topline Pro announced a $27 million Series B on August 14, 2025 and reports thousands of SMBs using the platform. A self-serve “Try for free” path sits alongside sales-led plans. This model is easier to assess than a broad enterprise platform, while creating different buying and delivery risks: SMB churn, seasonal demand, onboarding friction, and the economics of supporting local operators.

The prospecting question is whether an agency can improve activation without weakening the product’s vertical focus. Home-services workflows connect discovery, lead response, quoting, scheduling, reviews, and payment collection. Friction in one stage can reduce the value of the rest.

Sell workflow fluency, not generic capacity

A credible partner should demonstrate knowledge of contractors, crews, local search, customer calls, and cash collection. Useful entry points include:

• Vertical product engineering: Refine contractor workflows for crews, dispatch, quotes, and payment collection.
• Local-market features: Improve location-aware website, review, and lead-handling experiences.
• Activation and onboarding: Shorten the path from free trial to a functioning business operation.
• Integration delivery: Connect payments, invoicing, calls, and customer records without splitting the user journey.

Limited public pricing and sales-led access make a full outside evaluation difficult. That constraint favors a narrow diagnostic over a broad growth proposal.

Targeting decision: Treat Topline Pro as a focused vertical account with moderate onboarding and integration friction. Monitor Sidekick AI, payments, home-services integrations, and activation releases. Lead with a quote-to-payment or lead-response audit, and position the agency as a partner that understands local operators rather than as a general software vendor.

Series B Companies, 7-Way Comparison

Product	Implementation complexity	Resource requirements	Expected outcomes	Ideal use cases	Key advantages
NetBox Labs	Medium–High, CMDB migration and enterprise deployment	Network/IT engineers, automation tooling, change management, enterprise budget	Single source‑of‑truth, reduced config drift, faster automation & governance	Large networks, datacenter operations, teams modernizing infrastructure	Open‑source community, plugin ecosystem, enterprise features, AI grounding
Method Financial	Medium, API integration plus compliance onboarding	Engineering for APIs, compliance/legal review, creditor integrations	Real‑time liability discovery, direct payments, improved conversion	Fintechs, banks, lenders needing liability/payments connectivity	Broad coverage (20k+ institutions), payment initiation + liability matching
Hypori	High, virtualization, secure deployments, FedRAMP/SOC2 compliance	Security/compliance teams, federal procurement, specialized ops	Zero‑trust BYOD, isolated virtual workspaces, minimized device data risk	Government, defense contractors, regulated enterprises	Federal/defense validation, SOC2, FedRAMP in‑process, strong privacy posture
Spellbook	Low–Medium, integrations (Word) and model governance checks	Legal teams for evaluation, IT for integration, enablement for accuracy	Faster drafting/review, consistent clauses, scaled legal productivity	Corporate legal teams, law firms, contract‑heavy organizations	Word integration, clause libraries, free trial, rapid product cadence
Aiera	Low–Medium, streaming, transcription, and SDK embedding	Research/IR teams, light engineering for SDKs, subscription & procurement review	Sub‑second transcripts, AI summaries, faster event research throughput	Investor relations, equity research, financial analysts	Real‑time transcription & summaries, mobile apps, extensive event coverage
Outset	Medium, study design, participant recruitment, enterprise controls	Research ops, participant recruitment or BYO lists, analysts to act on synthesis	Rapid, scalable qualitative insights, synthesized themes & highlights	Product/UX research, CX teams, global/multi‑language studies	AI‑moderated interviews at scale, 40+ languages, enterprise case studies
Topline Pro	Low, self‑serve with optional sales assistance	Minimal tech for SMBs, marketing ops, subscription budget	Automated marketing, 24/7 lead handling, quoting and payments in one stack	U.S. home‑services SMBs (plumbers, HVAC, contractors)	All‑in‑one SMB stack, marketing & SEO automation, proven traction

Turn the Roster Into a Defensible Pipeline Segment

The seven accounts shouldn’t become a broad “Series B companies” campaign. They represent different sales environments, technical problems, and authority requirements. Method Financial and Hypori demand compliance-aware delivery credibility. Spellbook, Outset, and Topline Pro offer faster product and content angles. NetBox Labs and Aiera require specialist authority in infrastructure and financial data.

A Series B label helps identify expansion intent, but it doesn’t tell an agency what to sell. The useful account-selection system combines the funding event with product surface, buyer friction, and a visible trigger. A new SDK release points toward integration work. A security update points toward enterprise enablement. A new vertical product points toward workflow engineering.

Choose one vertical and one geography before building the campaign. A 100–500-person agency can’t credibly own every funded software category at once. It can own a technical problem inside a defined market, publish evidence around that problem, and map a focused set of accounts whose product direction creates a credible reason to engage.

That means building authority before outreach. A technical landing page, a product teardown, and a buyer-specific sequence will outperform a generic “we can help you scale” message because each asset proves that the agency understands the account’s operating constraints.

100Signals is one relevant execution option for agencies that need to move from a researched Series B segment to 200–500 mapped target accounts and 1,000–5,000 contacts, using niche validation, authority building, outbound sequencing, positioning scans, and market-report offers. Those are supplied service capabilities, not guaranteed results. Agencies can also use B2B lead generation tips to strengthen the broader execution plan.

The competitive position is simple: don’t chase every funded company. Select the account tier where your technical proof is strongest, publish around the problem before contacting buyers, and make each outreach message reference a product surface that can plausibly need your help. That’s how Series B funding becomes a defensible pipeline segment rather than another noisy prospect list.

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Choose one vertical, geography, and technical problem from this roster, then request a free positioning scan from 100Signals to test whether your agency can own that niche before competitors do.