How to Vet a Software Development Partner: CTO’s Checklist

I've built partnerships with over 200 clients, and I can tell you which ones thrive versus which ones collapse two sprints in. It's not about how great they are at coding, though that should be a given. A good partner actively takes part in decision-making.

There are simply too many leaders who come at software development collaborations in the same way one would order takeout. They hand over their specs and expect a plug-and-play solution that they can integrate into their workflows. But these kinds of solutions require architectural judgment: should we use microservices or a monolithic architecture?? What cloud-native patterns go along with their AWS stack? How do we architect APIs that won't shatter at their desired scale?

These decisions need to be made at the intersection of business and tech, and that's what real partnership looks like. When you're vetting a development partner, you're not hiring code scribblers (an AI could do that reasonably well). You're selecting technical co-pilots for risk management, architectural foresight, and smooth collaboration on your project.

My biggest red flag: any partner that merely rubber-stamps your technical choices. The greatest client relationships started when we pushed back on their initial direction. We pushed back on database choices, warned against over-engineering solutions, advocated for security by design, and highlighted potential GDPR compliance risks. Great partners think in systems and the long-term product strategy. Delivering features on time no longer impresses anyone.

My checklist comes from decades of successful collaboration and watching my competitors crash and burn. No theory — just practical filters that tell strong collaborators from mediocre coding gurus.

Tech Stack: Are You Speaking the Same Architecture Language?

This is the catch with tech compatibility across teams: it's not a question of the tools themselves, it's the mindset of the people building the software and whether that aligns with the product owner's vision. I've seen partnerships fail because one team were microservices zealots who wouldn't let go of their obsession, and the other just needed to get a monolith out the door. The thing is, there's no right or wrong in these decisions. The partners need to be on the same page when it comes to architecture that works for their particular case.

When you're checking if a software development studio has the right stack and workflow, don't just check if they use React or Vue. Make sure they can tell you how they get to architectural decisions. Do they document the big decisions? Do they have a strategy for avoiding tech debt? Under stress to get something done, do they cut corners mindfully, or do they just hack something together to get them across the wire?

When evaluating their coding, look beyond languages, frameworks, and libraries. Try to find out:

• How do they approach service architecture, and how do they handle communication between services?
• What is their approach to maintaining full observability and handling failures?
• How do they balance going for high development speeds with a clean codebase that is scalable?

We always start our partner relationships by showing our decision-making process first hand — how we evaluate trade-offs, document architectural decisions through ADRs, etc. We're not trying to impress anyone. We are laying the groundwork for a healthy and productive collaboration.

A team can be thoughtful enough to dedicate half the sprint to reducing debt, but then they have a partner who thinks that's just a waste of time. Check for compatibility before you jump-start the project.

And again, anyone can talk a good game during pitches, so it's also a good idea to start with a test run. Give them the chance to prove themselves with a small MVP, and then move on to a strategic partnership.

Process & Delivery: Can They Align with the Ways You Ship?

Yeah, I know, and I've heard how everyone now talks about being "agile". Don't fall into that trap too quickly, though. Half the industry is still pushing code through waterfall. It's just a flashy daily standup slapped on top of it, where a lot of the times the developers use it as a way to chill with a muted mic.

Running development teams for the past decade, I have found that flawless Jira boards and sprint ceremonies are useless if your team cannot explain to you why they are building something. The collaborations that fail are the ones where developers merely burn tickets without trying to understand the business context.

For instance, if a company has to redesign their checkout process because of high cart abandonment rates. Or one of the critical APIs goes down and you need an immediate solution. It's when something like that happens that you find out if your partners are actual thinkers or just grunt soldiers spewing lines of code.

Teams that go through this a dozen times in a month handle curveballs easily. At Pynest, we never wait until deploy to let our clients know that the payment processing integration is going to be a problem. We have those conversations early and we're not afraid to push back when we see requirements that don't make sense for what the client is trying to achieve.

Every single one of our projects has a technical delivery lead — someone who knows the code. A team lead can explain to the client why a rewrite of the auth system at this stage will save us three weeks later. They're an architecture consultant.

We use our own CI/CD, linters, and test coverage standards unless the client has their special workflows set in stone. We care about the product and where it's heading, so we optimize the code so it becomes the fine-oiled engine that drives business results. Investing 20-30% of each sprint in code optimization and codebase health is an indication of a proactive tech team.

If a team approaches specs like a checklist, without any enthusiasm, it’s not a team I’d go for—I prefer strategists. That said, some companies prioritize strong executors, and in that case, it works for them. Just make sure to ask the hard questions upfront, so you don't get disappointed mid-sprint.

Security & Compliance: How Seriously Do They Take Risk?

Conversations about security usually follow two paths: either the business wants their development partner to "handle it" without a clue as to what that means, or they provide a checklist of compliance and expect tech magic.

Smart dev teams approach security differently. It is part of development right at the start of sprint planning, so it is not a checklist that you go through at the end. Look for teams where developers are familiar with STRIDE methodology and can demonstrate how they identify spoofing, tampering, and elevation of privilege threats at the stage of software architecture design.

The question to ask them: who actually owns security on their team? Good partners will tell you that everyone does, but in the real world, the lead developers are usually responsible for secure coding practices. Our DevSecOps lead engineers include SAST and DAST in every CI/CD pipeline, map out how we store and handle PII, manage access controls, and oversee API security from a business perspective.

Threat modeling should be done ahead of time –  not just for HIPAA or SOC 2 projects, but for all projects. At Pynest, we map data flows, identify trust boundaries, and model possible attack scenarios before our developers even touch the keys and write their first line of code. It usually pays off in the long run. Whether you're handling payment data or basic customer information from their profile, the best approach is to design as if you might need enterprise-grade compliance in the near future.

How do you make sure the team gets this? Ask what's gone wrong in past projects. Security approaches are not proven by perfect track records. It's about learning from the breaches and building stronger defenses. Teams that claim they've never had security issues probably haven't been in the trenches.

Industry Experience: Do They Know Your Context?

I've managed teams that could build anything from distributed systems to machine learning pipelines, but put them in a heavily regulated industry and suddenly they're like fish out of water. That's why at Pynest, we've established niche software architecture guidelines, and we have teams that specialize in coding for specific industries. So when the time comes, we're ready for the challenge. But it wasn't always like that.

Let's take fintech, for instance. We had a fantastic team that built a payment system with textbook architecture. The only catch is, they failed to understand that, in this particular corner of the business, race conditions on multi-threaded transactions don't simply become bugs – they’re compliance nightmares that can kill a product. 

Our developers had to learn PCI-DSS guidelines and idempotency architectures on the fly. We didn't want to screw it up before the auditors, but we did anyway. It's a good experience. I'm grateful we had that because today we handle security and compliance issues in fintech confidently.

Healthcare is even harder to crack, as every line of code there needs to be examined for legal compliance. My team once developed what they thought was a decent patient dashboard. Then we realized that the database module exposed PHI when data was being pulled and shipped. All it took was a simple patch of 15 lines of code.

HIPAA doesn't concern itself with how hard you work to encrypt or authenticate. If you're spilling as much as a single strand of protected information, you're liable. Figuring it all out took time, but we've got that behind us now, we've got the experience, and that's what it's all about.

Edtech also taught us some lessons. Most public schools run on tight budgets, with classes having obsolete hardware and terrible internet. Building lightweight APIs that work on 2G connections and maintain access privileges for students, teachers, and parents? Yes, we made it there, and that's something you're not going to find in the documentation. It only comes from watching your React app crawl on a 2015 Chromebook.

Niche knowledge comes from these kinds of battle scars. It's the kind of insight that you can't get from hackathons or online gatherings. We now assign teams to business cases that are familiar to them. So, I don't have to explain why audit trails need to be immutable or why certain workflows need multi-factor authentication. They ask the right questions when the project kicks off and spot regulatory landmines early.

Cortex's 2024 developer productivity report shows that 72% of software development teams wait over a month for new developers to contribute their first three meaningful pull requests. For 18% of the teams, it takes as long as three months. The same study found that in 58% of the teams, developers are not productive for five or more hours a week. The top cause for this stalling is "time spent gathering project context". Clearly, experience and niche expertise are two very important aspects in developer resumes.

Ask your teams for examples that go beyond “we built an app in fintech once.” Ask why they made certain decisions, what challenges they ran into, and what they’d do differently now. Check for more than impressive case studies — you're looking for lessons learned.

Team & Soft Skills: Will They Challenge You — or Just Execute?

A few months ago, we took on a fintech client who wanted a real-time fraud detection solution. It was a small startup with around 50k daily transactions. Their previous system relied on rule-based alerts and manual reviews. In our first architecture meeting, they immediately suggested gradient boosting, which seemed to them like the obvious ML approach for the project.

Most dev shops would just nod and start coding. We asked them the hard questions: "What about dynamics? Your transaction patterns change every season, and we need monitoring to keep the ML models from degrading." The client's product owner got agitated at first — they didn't need solutions with bells and whistles.

Our lead engineer talked some sense into them. We'd seen this before. Models that work well in training become false positive factories in production. And then you get a legitimate transaction flagged by the system. International transfers get blocked during market hours. Recurring subscriptions with the slightest transaction amount changes would be treated as anomalies.

We could have built exactly what they asked for – clean code, elegant features, deployed on schedule. Instead, we pushed back and spent an extra week designing for the real-world conditions.

Six months later, their fraud detection runs at 0.3% false positives while catching 94% of actual fraud. Their previous "exactly as specified" solution would have been deprecated by month three.

The best client relationships start with us saying "no" to something. It's not about us being defensive or trying to show off our technical prowess – we're protecting their long-term success over our short-term revenue.

We handle scope changes proactively. When something changes, we assess the impact immediately and align the client's expectations with the current design and capabilities of the software.

I suggest you look for these qualities in your partner. Do they ask questions to align technical design with business requirements or do they just nod through the meeting? Do their engineers discuss both the deliverables and the trade-offs? If you suggest something risky, do they push back?

Reputation & Longevity: What Their Past Clients Say Without Saying It

Portfolios can be misleading. They often carry marketing fluff and lack complete context. Sure, they tell us a lot about the company's experience, but if I were choosing a partner, I'd definitely dig deeper.

Who’s still working with this team after 18+ months? I'm not speaking of rapid MVP builds, but businesses that added scope, returned for a follow-up project, or even referred them to their partners.

Another clue is the people who are working there because their coding culture is what makes the foundations of your product. Pay attention to the core engineering team. Have they been there from the start, or are they rotating every 6-9 months?

I would say that high turnover is a serious red flag. From what I know, tech companies have an average rate of 13-18% per year. The good ones, though? They keep it under 10%. So I would suggest stalking their LinkedIn a little, and find out who they actually are behind the scenes.

Review platforms matter, but read between the lines. Skip Clutch reviews that sound like they were written by the same marketing intern. Look for detailed reviews from different clients, spaced years apart, where they describe actual technical challenges and how the team struggled to make their product work. If all you see are clone reviews, then I'd advise against partnering with them.

Finally, ask your future partner: "Can I speak with a client you've worked with for over two years?" If they dodge or continue spamming you with pitches about their portfolio, walk away. If a former client mentions running into critical issues every sprint, but says the team resolved them, then that's a sign of growth. Being 'lost in translation', or consistently growing technical debt — that is not a good sign.

Picture your codebase in 12 months, and work backward. Choose a partner willing to align with your vision, not just execute documented scope.

Final Thoughts: A Good Dev Partner Doesn’t Just Ship Code — They Reduce Risk

Having been more than 15 years in the trenches as a CTO, here’s my checklist for singling out teams that really deliver:

• Identify if they push back against unrealistic deadlines. Strong partners say no to impossible deadlines and explain why. Weak ones accept your money and fail at all the milestones.
• Can they design for your scale? Anyone can draw boxes and arrows. Try to think beyond that and see how they conceptualize architecture. What I'd like to hear are some sharding plans for the databases, levels of cache, and how they weathered 10x traffic spikes.
• Find if their DevOps culture is one you can work with. If you're planning a CI/CD with automated testing and they manually deploy on Fridays, it's a culture war in the making.
• Is there a dedicated technical lead? There should be one person—not a committee—responsible for hitting deadlines. Ask what their name is, and if they won't answer, walk away.
• If compliance matters, don't forget to ask whether it is integrated into their design process. Ensure that security by design practices are there, and they plan out HIPAA, SOX, and GDPR compliance from day one.
• Are they proactive about avoiding tech debt? The best partners catch problems while they plan their sprints, not when it's three months into production and almost time to deliver.
• Can you reach their long-term clients? You want to talk to companies that they've helped through significant infrastructure migrations or product ecosystem expansion.

A valuable partnership is more than coding, processes, and best practices. Find partners who think like CTOs and not just contractors running through your scope, not a care in the world. Don't settle for an executor who tells you that you're not living in the real world. 

Look for technical leaders who can visualize what you're trying to build and work within the constraints to get you there.