The Startup Red Flags I Missed (And How You Can Spot Them First)

Two years. That's how long I stayed at a startup circling the drain from day one. When I finally left, I'd passed on other offers, watched my equity become worthless paper, and spent countless nights debugging a codebase held together with duct tape and denial.

The worst part? The startup red flags for software engineers were everywhere. I just didn't know how to read them.

My background wasn't traditional. Five years managing restaurants, then a coding bootcamp. So when I landed what felt like a "real" tech job, I ignored my gut completely. The fancy office, the charismatic CEO, the promises of rapid growth. I wanted it to be real.

But learning to spot warning signs isn't pessimism. It's professionalism. And if I'd spent even half the time researching my employer that they spent vetting me, I'd have seen what was coming.

This is the framework I wish someone had handed me before I signed that offer letter. Consider it your startup job offer evaluation checklist for engineers, built from expensive mistakes.

The Interview Theater: 6 Red Flags Hidden in How They Sell You the Role

Pay attention during interviews. They tell you everything. Here's what I missed:

1. They couldn't articulate what success looks like in 90 days. When I asked what my first three months would look like, I got vague hand-waving about "hitting the ground running" and "wearing many hats." Translation: they had no plan.

2. Every interviewer gave a different company pitch. The CEO talked about enterprise sales. Their engineering lead mentioned consumer growth. Product was focused on a pivot they'd just decided on. Nobody was aligned.

3. They rushed me through the process. First call to offer in five days. At the time, I felt special. Now I know better: healthy companies don't make major hiring decisions in a week. They were desperate.

4. The technical interview was suspiciously easy. My bootcamp projects were more challenging than their take-home assignment. Low hiring bars often mean high tolerance for poor engineering practices.

5. They avoided specifics about the team I'd join. "You'll be working across the stack with different teams" meant "we don't have enough engineers, so you'll be doing three jobs."

6. The sell was too hard. Their CEO spent 45 minutes telling me why this was the opportunity of a lifetime. Confident companies let you ask questions. Desperate ones keep talking.

[Link: How to evaluate a tech job offer]

Follow the Money: 5 Financial Warning Signs Most Engineers Never Think to Check

I'm a frontend engineer, not a finance person. That's exactly what I told myself to avoid doing basic research. Don't make my mistake.

How to tell if a startup will fail before joining as an engineer often comes down to following the money:

1. Check their funding timeline. My startup had raised a Series A eighteen months before I joined and was "about to close" their Series B. That round never materialized. Use Crunchbase or PitchBook to see when they last raised. If it's been more than 18 months without clear profitability, ask hard questions about runway.

2. Look for layoff history. A simple LinkedIn search for "[Company Name] layoff" or checking Layoffs.fyi would have shown me they'd cut 30% of their team eight months before I joined. They never mentioned it.

3. Research their burn rate signals. Suddenly moving to a cheaper office? Freezing perks? These aren't "cost optimizations." They're survival tactics.

4. Ask directly about runway. "How many months of runway do you have at current burn?" is a legitimate question. Any hesitation or refusal to answer is itself an answer.

5. Understand their business model. For two years, I built features without ever understanding how we'd actually make money. And the answer was: we wouldn't.

The People Signals: Reading Engineering Team Health Without Inside Access

You can learn a lot about toxic startup culture warning signs without ever stepping inside the building.

Start with LinkedIn. I should have noticed that average tenure on their engineering team was eleven months. Why didn't I wonder about three engineering managers in two years? Why didn't I reach out to those people who'd left?

Glassdoor reviews require context, sure. But patterns matter. When eight different people mention "poor communication from leadership" or "constantly shifting priorities," that's data.

One move I use now: asking to speak with someone on the team who wasn't part of my interview loop. Companies that refuse this request are hiding something. My startup wouldn't let me talk to anyone the CEO hadn't pre-approved.

Questions to ask a startup CEO before joining that reveal team health:

• "What's your current attrition rate on the engineering team?"
• "Can you tell me about someone who left recently and why?"
• "How do you handle disagreements between engineering and product?"

Watch their body language. Listen for deflection.

One more thing: Google the executives. My CEO had a trail of failed startups and burned relationships that a ten-minute search would have revealed. I didn't look.

Technical Debt Tells: What the Codebase and Stack Choices Reveal About Leadership

Signs a startup will fail before joining often hide in plain sight in their technology choices.

During my interview, they bragged about using "cutting-edge" technology. What they actually meant was: we chase every new framework, have no standardization, and you'll spend most of your time navigating chaos.

Red flags I'd look for now:

No tests. When I asked about their test coverage, I got a laugh and "we move too fast for tests." We also moved too fast for stability, reliability, or sleeping through the night without PagerDuty alerts.

Everything is urgent. A startup that can't distinguish between important and urgent has no engineering leadership. Every sprint at my company was a fire drill.

Stack decisions made by vibes. Ask why they chose their stack. If the answer is "our CTO read a blog post" rather than "we evaluated options against our specific needs," that tells you about decision-making culture broadly.

Documentation is "on the roadmap." It's not. It never will be.

If you can, ask to see a sample pull request or deployment process. The gap between what they say and what they actually do will be illuminating.

[Link: How to evaluate engineering team culture]

The Equity Trap: Red Flags in Compensation That Look Like Opportunities

Let's talk about startup equity compensation red flags, because this is where I really got burned.

My offer came with what sounded like a generous equity package. Nobody explained any of this to me:

1. Percentage matters more than number of shares. I was offered 10,000 shares. Sounds great until you learn there were 100 million shares outstanding. I owned 0.01% of a company worth very little.

2. The strike price tells a story. My options had a strike price that suggested a $50 million valuation. The company had $2 million in ARR and no path to profitability. That valuation was fantasy.

3. One-year cliffs protect companies, not employees. I hit my cliff right before things got bad enough to force me out. Convenient for them.

4. Acceleration clauses matter. Without double-trigger acceleration, your equity means nothing in an acquisition. Mine had no acceleration. Most don't.

5. Exercise windows are often traps. When I left, I had 90 days to exercise options that would have cost me $40,000 for shares in a company I knew was failing. I let them expire.

What red flags should engineers look for when joining a startup in equity conversations? Any unwillingness to share the cap table, total shares outstanding, or latest 409A valuation. If they won't tell you, assume the worst.

[Link: Understanding startup equity compensation]

Your Pre-Offer Due Diligence Checklist: 15 Questions to Answer Before Signing

This is the startup job offer evaluation checklist for engineers I use now. Answer these before you sign anything:

Financial Health:

1. When did they last raise, and how much runway remains?
2. What's their current revenue and growth rate?
3. Have they had layoffs in the past two years?

Team Health: 4. What's the average tenure on the engineering team? 5. Why did the last three engineers leave? 6. Can you speak with someone outside the interview loop?

Leadership: 7. What's the CEO's track record with previous companies? 8. How many executives have left in the past year? 9. How does leadership handle bad news?

Technical Reality: 10. What does the deployment process look like? 11. What's the test coverage, honestly? 12. How is technical debt prioritized?

Equity Clarity: 13. What percentage of the company do your options represent? 14. What was the last 409A valuation? 15. What's the exercise window if you leave?

How to research startup financial health before accepting a job: Use Crunchbase for funding history, LinkedIn for team tenure, Glassdoor for culture signals, and direct questions for everything else.

Look, I'm not saying never join a startup. I work at one now, and I love it. But I chose this one differently.

Three weeks of research before accepting my current role. Conversations with four former employees. Uncomfortable questions about runway while watching how leadership responded. Negotiations on my equity terms with full information about the cap table.

Sometimes walking away is the best career move you can make. I've turned down two offers since my bad experience because the startup red flags for software engineers were too numerous to ignore. Both companies have since had significant layoffs.

Trust your gut, but verify with data. If something feels off, investigate. If you can't get answers? That's an answer.

You're not being difficult by asking hard questions. You're being professional. Any company that reacts poorly to reasonable due diligence is telling you exactly what it'll be like to work there.

I lost two years to a startup that showed me who it was during the interview process. I just wasn't looking. You don't have to make the same mistake.

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Have questions about evaluating startup offers? I run a Discord community for bootcamp grads where we talk about this stuff regularly. Sometimes the best research is hearing from people who've been there.