Most engineering hiring mistakes come from hiring for the wrong stage. Learn which engineers to hire from Pre-Seed to Series C, and the mistake to avoid at each level.
The Right Engineer at the Wrong Stage Is the Wrong Engineer
Picture two hiring mistakes.
A seed-stage healthtech startup hires a Staff Engineer from a large public company. Brilliant CV. Deep expertise in distributed systems. Six months later, the product still hasn’t shipped. The engineer is building infrastructure for a scale the company won’t reach for years, and struggles with the chaos of having no spec, no team and no process.
A Series C startup hires a scrappy generalist who thrived at three early-stage companies. Fast, adaptable, great at building from zero. Six months later, they’re struggling. The role needed deep specialism in data platforms, and breadth isn’t enough to cover the gap.
Both engineers are talented. Both hires failed. The problem wasn’t the people. It was the stage.
Most engineering hiring mistakes happen because a company hires for the wrong level of maturity. The fix is a simple lens we call the Startup Hiring Pyramid.
This article covers:
- The four levels of the pyramid, from Pre-Seed to Series C
- Which engineers to hire at each level, and why
- The most common mistake at every stage
- How healthtech changes the picture
- How to work out which level you’re at
The Pyramid at a Glance
| Stage | Level | Who to hire | Biggest risk |
|---|---|---|---|
| Pre-Seed / Seed | Base | Founding generalists | Hiring for scale too early |
| Series A | Second | First leadership layer and senior product engineers | Wish-list specs and late leadership hires |
| Series B | Third | Scaling specialists and process builders | Headcount growing faster than capability |
| Series C | Top | Deep specialists and platform teams | Under-specialised hires in critical roles |
Each level builds on the one below it. Skip a level, or hire for the wrong one, and the structure wobbles.
Level One: Pre-Seed and Seed. Founding Generalists
What the company needs: A working product, fast. Usually with one to five engineers and no formal process.
Who to hire: Founding generalists. Engineers who build across the stack, handle infrastructure, talk to users and make product decisions without waiting for a spec.
Engineers dominate this stage. Carta found roughly 70% of first hires are engineers, and engineering makes up at least 45% of the first five hires.
These early hires shape everything. Brian Chesky described bringing in a first engineer as “like bringing in a DNA chip to the company.”
What to look for:
- Range over depth
- Comfort with total ambiguity
- Judgement about what to build properly and what to build fast
- A risk appetite matching an equity-heavy offer
- Trust with the founders, including the ability to disagree
What to pay: Equity carries the offer. The median equity granted to a first engineer is 1.54%, falling to 0.61% after only two more hires.
The common mistake: Hiring for scale too early. A Staff Engineer from a large company brings habits built for a world with process, specialists and stable requirements. At Seed, those habits slow everything down. Over-engineering burns runway the company doesn’t have.
Healthtech overlay: Your founding engineers make the first decisions about patient data, access and security. You don’t need a dedicated security engineer yet. You do need generalists who treat HIPAA as a design constraint from day one.
Level Two: Series A. The First Leadership Layer
What the company needs: Proof the product works at a larger scale, and a team able to deliver predictably.
Teams are leaner than they used to be. Series A companies now average 16 employees, down from 25 a few years ago.
Who to hire: Two types of engineers matter most.
1. The first engineering leader. A Head of Engineering or engineering manager who takes people management, delivery and process off the founder’s plate. CRV puts it clearly: “By Series A, you’re hiring a leader who will shape an entire engineering function.”
2. Senior product engineers. Experienced builders who own whole features, work closely with product and ship without close supervision.
What to look for:
- Leaders who have scaled a team from your size to two or three times larger
- Engineers who’ve worked at companies one step ahead of you, not five
- Builders who still enjoy ambiguity but bring more structure than founding engineers
When the leadership hire becomes urgent: Once a team grows past roughly 10 engineers, it tends to split into sub-teams. Sub-teams need coordination, and coordination needs a leader.
The common mistakes:
- Wish-list job specs. Series A specs often list every skill the team lacks. Strong candidates skip them. Define the 90-day problem instead.
- Waiting for an incident. Most startups hire their first engineering leader after an outage, a missed deadline or a burned-out founder. By then, the search is reactive.
Healthtech overlay: Enterprise customers start asking harder questions. Security questionnaires, integration requirements and compliance evidence arrive with the first big health system deal. Your first engineering leader needs experience shipping in a regulated environment.
Level Three: Series B. Scaling Specialists
What the company needs: Growth without losing speed. The team often doubles. Process starts to matter as much as talent.
Who to hire:
- Specialists in areas the generalists covered before: backend platform, data engineering, mobile, security
- Engineering managers to lead each new team
- Process builders who create hiring systems, on-call rotations, planning rituals and onboarding programmes
- Sometimes a new CTO or VP of Engineering, if the founding technical leader isn’t suited to running a 20-plus engineer organisation
What to look for:
- Specialists who still enjoy startup pace
- Managers who’ve built teams, not inherited them
- Leaders who measure output, not headcount
The common mistake: Headcount growing faster than capability. A team doubling engineering headcount isn’t necessarily doubling its output. Watch for the warning signs:
- Shipping speed flat or falling while the team grows
- Meetings and process growing with no matching gain in output
- Senior engineers leaving faster than you replace them
- Job specs getting vaguer as the team scales
These signals point to stalling engineering momentum. More hiring rarely fixes it. Better hiring does.
Healthtech overlay: This is often the stage for a dedicated security or compliance-focused engineer, and for integration specialists who know FHIR, HL7 and EHR vendors well. Domain ramp matters more now. One healthtech recruiting firm estimates engineers typically clear the healthtech domain ramp in four to six months. Plan onboarding around it.
Level Four: Series C. Deep Specialists and Platform Teams
What the company needs: Depth. Reliability at scale. Technical moats competitors struggle to copy.
Who to hire:
- Staff and Principal engineers who set technical direction across teams
- Platform teams owning developer experience, infrastructure and internal tools
- Dedicated data and ML functions
- Security and reliability engineering as full disciplines
What to look for:
- Proven depth in the exact problem you’re solving
- Experience operating systems at your target scale
- The ability to influence many teams without direct authority
The competitive reality: At Series C, you compete for talent against later-stage companies and public tech firms. Pay matters more than before. As of June 2025, the average salary for new engineering hires on Carta was about $189,000, and AI and ML engineering salaries have kept climbing faster than the wider market. Mission, technical ambition and autonomy have to do real work in your pitch.
The common mistake: Hiring generalists into specialist gaps. A versatile engineer who thrived at Seed often lacks the depth a Series C platform or data role demands. Breadth stops being enough.
Backfill risk peaks here too. Losing a senior specialist at Series C costs more, and takes longer to replace, than at any earlier stage. Retention and succession planning become part of the hiring strategy.
Healthtech overlay: Expect to hire for clinical AI evaluation, data governance and platform security as distinct roles. Health systems and payers now expect evidence of how models are validated, monitored and controlled.
Stage Transitions Are Where Hiring Breaks
The pyramid is not a straight line. Companies spend a long time between levels. Carta data shows the median time from Series A to Series B in 2025 was 2.7 years.
This matters for hiring. Your team will cross levels between funding rounds. A company might still be “Series A” on paper while needing Series B hiring patterns in practice.
Watch for these transition moments:
- Seed to Series A: The founders stop being the bottleneck on every decision. You need a leader, not another builder.
- Series A to Series B: One team becomes several. You need managers and specialists.
- Series B to Series C: Specialists need specialists. You need deep platform, data and security teams.
Many hiring mistakes happen in these transitions. The team keeps hiring for the level it used to be, not the level it’s becoming.
How to Work Out Which Level You’re At
Ignore your funding stage for a moment. Answer these questions instead.
1. How many engineering teams do you have?
- One team, or none: base level
- One team about to split: second level
- Several teams needing coordination: third level
- Many teams plus shared platforms: top level
2. What slows you down most?
- Building the product at all: base level
- Delivering predictably: second level
- Coordinating across teams: third level
- Depth in specific technical areas: top level
3. Who makes most technical decisions?
- The founders: base level
- One engineering leader: second level
- Several managers and leads: third level
- Staff engineers and platform owners: top level
If your answers point to different levels, you’re in a transition. That’s the moment to rethink your hiring plan.
Hire for the Level You’re Becoming
Every stage needs a different engineer. Seed needs builders who thrive in chaos. Series A needs the first leaders. Series B needs specialists and process. Series C needs depth.
The most expensive mistakes happen when companies hire for the wrong level:
- Specialists who over-build at Seed
- Generalists who under-deliver at Series C
- Leadership hires made after the incident, not before
Use the pyramid before every search. Ask which level you’re at today, and which level you’ll reach in the next 18 months. Then hire for the second answer.
Planning engineering hires for your next stage? Synaxia Group places senior software and product engineers into healthtech, medtech and biotech startups from Pre-Seed to Series C. We help you identify the right level for each hire, define the role and find engineers who’ve done it at your stage before. Get in touch with Synaxia Group to plan your next hire.