What Is the Decagon Interview Process Like? (Round by Round)

Candidates report five to six steps at Decagon. The process starts with a recruiter screen. Next comes a coding phone screen of about 45 minutes. Then a loop of about four rounds follows. Candidates report a 60 minute pair coding round and a 60 minute system design round. They also report a 60 minute deep dive on a past project, plus a behavioral conversation. Most candidates report three to four weeks from application to decision. Decagon is a young company, so exact rounds vary by role and level.

Quick Overview

Stage 1: Recruiter Screen

A short call about your background and interest. Expect the motivation question early. Prepare it with How to answer why Decagon.

Stage 2: Coding Phone Screen

About 45 minutes of live coding. Candidates report practical problems more than puzzle problems. Reported examples include an API implementation task with several parts and array problems at medium difficulty. Interviewers ask about running time and memory. Practice stating the time and space cost of your code as you write it.

Stage 3: Pair Coding Round

A 60 minute session where you build a small working feature. The interviewer acts as a teammate, not a judge. Ask clarifying questions, choose a sensible scope, and finish something that runs. Clean, tested code matters more than a clever trick.

Stage 4: System Design Round

The design questions follow Decagon's product. Candidates report questions about AI agent systems for customer support. Reported topics include knowledge ingestion and retrieval for support documents, using embeddings and vector search. An embedding is a list of numbers that represents the meaning of a text. Vector search finds the stored texts whose numbers are closest to a query. One reported onsite question involved an AI gateway with audit requirements. A gateway is one service that routes all requests to language models. Audit means every request can be traced and reviewed later. The full topic list is in What to expect in the Decagon system design interview.

Stage 5: Project Deep Dive

One hour on a project you led or built. Pick a project where you made the key decisions. Prepare the reasons, the alternatives you rejected, the numbers, and what broke. Interviewers probe until they reach the edge of your real involvement.

Stage 6: Behavioral Round

Decagon states four values in public: Just Get It Done, Invent What Customers Want, Winner's Mindset, and The Polymath Principle. The behavioral questions test for these directly. See Top Decagon behavioral interview questions for the question list and answer plans.

Timeline and Decision

Candidates report three to four weeks for the full process. Some report faster decisions, within about two weeks. Candidates rate the difficulty near the middle of the scale. The most common complaint is that the loop can feel long for a small company. The most common praise is strong, well prepared interviewers.

Questions to Ask Them

Every round ends with time for your questions. Use it as evaluation, in both directions. Good questions here: how agent quality is measured, how on-call works on a small team, and how engineers split time between product and customer work. Decagon expects engineers to work directly with customers, so ask what that looks like in a normal week. A specific question also proves you researched the product.

How to Prepare

• Drill practical coding. Grokking the Coding Interview teaches the patterns behind medium and hard problems.
• Practice product-shaped design. Grokking the System Design Interview covers the building blocks the agent questions use.
• Prepare one deep project story. Write down decisions, alternatives, numbers, and failures before the loop starts.
• Read the product pages. The interviews reward candidates who know what Decagon actually sells.