Standard developer interview processes are poorly designed for catching the problems that actually cost clients money: poor communication, inability to handle ambiguity, bad code quality disguised by good verbal explanation, and professional dishonesty about past work.
Here is the evaluation process that surfaces these problems before you have paid for the first month.
Step 1: Application review and initial screen (20 minutes)
Review their application and portfolio with specific goals.
What to look for in portfolios:
Can they describe what the technical challenge was, not just what the product does? "I built a mobile app for restaurant ordering" is weak. "The challenge was handling concurrent orders when multiple users checkout the same item simultaneously; I solved this with optimistic locking and a reservation queue" tells you they understand the technical substance of their work.
Variety of problem types. A developer who has only built one type of application (only e-commerce sites, only marketing websites) has a narrower range than someone who has solved different types of problems.
Evidence of production use. Live, real products being used by real people are better evidence than demo projects.
Initial screen (20 minutes, video call):
Cover why they are available, their rate expectations, and whether the basic logistics work (timezone, availability, start date). Do not spend 45 minutes here. This is a filter, not an evaluation.
Step 2: Technical screening (45-60 minutes)
The goal of technical screening is to verify that the candidate can actually do the core technical work required.
For a frontend developer: Share a Figma design or a specification. Ask them to walk you through how they would approach implementing it. What questions do they ask? What decisions do they make? What trade-offs do they consider?
For a backend developer: Describe a data model problem and ask them to reason through the schema design. Or share an existing piece of code and ask what they would improve and why.
What you are evaluating:
Not whether they get to the "right" answer, but how they think through the problem. Do they ask clarifying questions before diving in? Do they consider edge cases? Do they think about performance implications? Do they communicate their reasoning, or do they just produce output silently?
The thinking process is more revealing than the answer. A developer who reaches a suboptimal solution while demonstrating good problem-solving process is often more valuable than one who gets the right answer by rote.
Step 3: Communication evaluation (throughout the process)
Communication quality is evaluated across the entire process, not as a discrete step.
Written communication:
How detailed and clear are their email responses? Do they ask specific questions or vague ones? When they describe their previous work in writing, is the description specific or generic?
Weak: "I have worked with many different technologies and can adapt to your needs."
Strong: "My previous project used Next.js 14 with a PostgreSQL database through Prisma, deployed on Vercel. The main technical challenge was real-time inventory sync across locations; I implemented that with WebSocket connections to a Redis pub/sub system."
Response time:
How quickly do they respond to messages? This predicts communication responsiveness during the engagement.
Questions they ask:
Good developers ask good questions. Before the technical screening, do they ask about the type of problems they will be solving? Do they ask about the tech stack? Do they ask about the team they will be working with? An absence of questions suggests either overconfidence or lack of engagement.
Step 4: Paid test project (2-3 days)
This is the most important step and the one most often skipped.
Define a real piece of work from your backlog that is bounded and evaluable. The test project should:
- Involve the core technical work of the role
- Be completable in two to three focused days
- Have clear acceptance criteria so you can evaluate it objectively
- Include at least one ambiguity that requires the developer to make a decision or ask a clarifying question
What you evaluate during the test project:
The work quality. Does it meet the acceptance criteria? Is the code readable and maintainable? Are edge cases handled?
Communication during the project. Do they ask clarifying questions when they hit an ambiguity, or do they make assumptions silently? When they hit a blocker, do they report it or try to work around it without telling you?
Estimation accuracy. How does their actual time-to-completion compare to their estimate? The best predictor of future estimation accuracy is past estimation accuracy.
Step 5: Reference checks
Ask for two or three references from clients or employers on specific projects. Generic references ("great to work with") are not useful. Ask specific questions:
"Can you describe what [developer] contributed to [specific project]?"
"Were there any moments where the project ran into difficulty? How did they handle that?"
"If you were hiring for a similar project today, would you hire them again?"
The last question produces the most honest answers. Reluctance to say yes unambiguously is a signal.
Red flags that predict problems
In the interview:
- Vague answers about specific previous work ("I have worked on many different types of projects")
- Inability to describe a time something went wrong and how they handled it
- Overconfidence without corresponding technical substance
- Claiming sole credit for team projects without mentioning the team
In the test project:
- Missing deadlines without communication
- Submitting work that does not meet the stated acceptance criteria without acknowledging the gap
- Making major assumptions without asking about them
- Writing code that works but is unreadable or unmaintainable
In references:
- Short answers with no specific detail
- "Great" as the only adjective used without elaboration
- Reluctance to elaborate when asked about specific projects
See how we staff dedicated developer teams and the evaluation process we use internally. Get in touch if you want to discuss what the right interview process looks like for your specific hiring situation.