SpellInterview

Inspiration

We were inspired to build SpellInterview after seeing how challenging technical interviews can be for talented developers who struggle to clearly express their thoughts under pressure.

Working in a large IT company, I often hear stories from colleagues who conduct technical interviews. One thing comes up again and again: candidates may have strong technical knowledge, but explaining their reasoning, structuring their thoughts, and communicating solutions out loud can be surprisingly difficult.

That made us realize that preparing for an interview shouldn't be only about knowing the right answers. It should also be about practicing how to communicate what you know.

We created SpellInterview to give developers a safe space to practice answering interview questions out loud, build confidence, and get better at turning their knowledge into clear, structured answers.

What it does

SpellInterview simulates the experience of a real technical interview.

The app presents interview-style questions and lets users answer them out loud, just as they would when speaking with a real interviewer. AI then analyzes each response, evaluates how well the user answered the question, and provides actionable feedback on what could be improved.

After completing an interview session, users receive an overall score and can review their performance question by question. For each answer, they can see personalized recommendations and learn how to make their response clearer, more complete, and better structured.

The goal is not just to help users learn interview answers, but to help them practice actually saying those answers out loud — building both their knowledge and confidence before the real interview.

How we built it

SpellInterview was built as a small family project — by me, my wife, and our one-year-old, who was always eager to contribute to the development process, although her contributions were not always productivity improvements. :)

We naturally divided the work based on our strengths. My wife focused on marketing, documenting our journey, and sharing posts about how the product was evolving, while I focused on the technical side and building the application itself.

For the technical stack, we built the iOS app natively using Swift and SwiftUI. The backend is powered by Symfony, with PostgreSQL handling our data storage. We also integrated RevenueCat to manage subscriptions and in-app purchases. We wanted to keep the architecture practical and reliable while giving us enough flexibility to grow the product as more people start using it.

We decided to start with iOS so we could stay focused and build the best experience possible for one platform rather than trying to do everything at once. Our priority was to create a simple and polished experience where users could focus on what really matters: practicing how they communicate during an interview.

If we see that SpellInterview genuinely helps people become more confident and better prepared for interviews, we would love to take the next step and bring the experience to Android as well.

What we learned

One of the biggest things we learned is that building the app is only one part of building a product.

As developers, it is easy to focus on the technical challenges, but we quickly discovered that writing code was often the most straightforward part. Marketing the product, understanding how to reach the right people, planning what to build next, prioritizing features, and making decisions with limited time and resources turned out to be just as important — and often much harder.

This experience taught us to think beyond the code and look at SpellInterview as a product: not just something that works, but something that solves a real problem, reaches the people who need it, and can continue to grow.

What's next for SpellInterview

The next step for SpellInterview is simple: get it into the hands of more people and learn from how they actually use it.

We want to see how the app performs as the number of users grows, understand where the experience can be improved, and most importantly, listen to feedback from the people preparing for their interviews with SpellInterview.

We also know that putting a product into the real world will reveal things we could never discover during development. There will probably be bugs, unexpected use cases, and ideas we haven't thought of yet — and that's part of the journey.

Our goal is to stay close to our users, respond to their feedback, fix problems quickly, and continuously make SpellInterview a better place to practice, improve, and walk into interviews with confidence.

For now, SpellInterview is focused on iOS, but if we see enough demand from our users, we would also love to bring the experience to Android in the future.