Engineering Roles & Responsibilities Matrix

Purpose

This matrix defines the engineering levels at NextDay AI. We use it to validate the level of each engineer, to run better interviews and skill evaluations, and to show every engineer a clear direction for growth. Every level is described against the same seven dimensions, so levels can be compared directly and you can see exactly what changes from one to the next.

Levels are cumulative

A Senior Engineer is expected to meet everything from the Junior and Middle levels too — and so on up the ladder.

Owners, not executors

We want Fullstack engineers who can deliver across the whole stack. Everyone is stronger in some areas than others, and that's fine — but every engineer, at every level, is expected to care about the product and act like an owner.

Built on a baseline

These levels build on our shared baseline. Read Engineer Responsibilities & Ownership first — ownership, Definition of Ready, quality gates, and the “hands on the wheel” AI rule.

Shared foundations

On top of every level, all engineers apply our core practices — KISS, DRY, SOLID, separation of concerns, and functional / reactive / event-driven / declarative approaches. See the source doc for the full list.

The ladder

How to read this

▸ The seven dimensions every level is measured against

At a glance

Tip: click any cell to open the full description for that role and dimension. Scroll the table sideways on narrow screens.

Roles in detail

Delivery & leadership structure

The ladder above describes how an engineer grows. This section describes how the team is organized to deliver — a hybrid model where people management, technical influence and delivery accountability run in separate lanes. It complements the craft ladder rather than replacing it. Squads are kept small and senior-heavy — at least two senior engineers each for redundancy and to seed new squads as the org grows.

Reporting lines

Lines show who reports to whom, not seniority — the ladder above is the source of truth for level. For example, a Staff Engineer sits a notch above a Tech Lead on the ladder, though both report into the Director.

Delivery — the Engineering Manager’s squads

Reports to (line management) Advisory Delivery Lead — a hat, not a reporting line

The most senior role inside engineering, reporting directly to the CTO. Sits across the whole department — the feature-delivery squads (through the Engineering Manager(s)), the specialised squads (Platform and Data), and the Tech Leads and Staff Engineers — and carries accountability for how the entire engineering organisation performs.

Reports to: The CTO
The most senior role within engineering; reports directly to the CTO and translates company direction into how the engineering department runs.
Span: Every squad, lead & Staff Engineer
Sits across the entire department — the feature-delivery squads (via the Engineering Manager(s)), the specialised squads (Platform and Data), and the Tech Leads and Staff Engineers. Everything engineering ships ultimately rolls up here.
Direct reports: Tech Leads, Staff, EM(s), Platform, Data, QA
Tech Leads, Staff Engineers, the Engineering Manager(s), the Platform Engineering Manager, Data and the QA Lead report directly into the Director.
Foundations & health: Owns the foundations & overall health
Accountable for establishing strong engineering foundations and for the overall health of the department — the standards, architecture direction and ways of working everything else is built on.
Velocity & execution: Lifts velocity & quality at scale
Owns and improves the velocity of the team, and ensures squads deliver high-quality, scalable solutions efficiently across multiple public-facing applications.
Process & culture: Architects & lands the processes
Architects and successfully implements the processes — collaboration, code review, testing, DevOps — that let a growing team work well, and scales the engineering culture as the organisation grows.
Partner with product & business: Aligns engineering with company goals
Partners with Product and the business to align engineering priorities with company objectives, balancing technical innovation with business needs.

Hats

A hat is a responsibility someone wears on top of their role — it is not a level and not a reporting line. Hats are assigned, can move between people over time, and carry accountability without people-management authority. We use two kinds: a delivery hat on each squad, and craft hats that raise the bar across a discipline.

🎩Delivery Lead

Delivery hat

Worn by a Senior Engineer on a squad — accountable for getting the squad’s project shipped.

Worn by: One of the Senior Engineers on the squad. The hat can move between senior people over time.
Carries: Delivery accountability — runs the daily stand-up, manages the day-to-day mechanics of getting work across the line, and surfaces risk to delivery early. Not people-management authority: the rest of the squad does not report to the Delivery Lead, and line management stays with the Engineering Manager.
Beyond the squad: Represents the squad in roadmap alignment sessions — gives status on the squad’s projects and picks up context on what other squads are building.

🔧Backend Lead

Craft hat

Raises the bar on the backend — best practices, knowledge-sharing and AI ways of working.

Worn by: A strong backend engineer — often someone already operating as a Tech Lead.
Carries: Fostering best practices across the backend; sharing the cool things they’re building or have discovered; and spreading ideas — including AI best practices — so the whole team levels up.
Not: A reporting line or a level. It’s a community-of-practice responsibility, not authority over people.

🎨Frontend Lead

Craft hat

The frontend counterpart — best practices, knowledge-sharing and AI ways of working across the frontend, web and native alike.

Worn by: A strong frontend engineer covering the whole frontend craft. React Native is just another frontend, the same way React web is — there is no separate mobile discipline; web and native both sit under this one craft.
Carries: The same craft leadership as the Backend Lead, for the frontend across web and native: fostering best practices, sharing ideas and what they’re working on, and spreading AI ways of working across the team.
Not: A reporting line or a level — a community-of-practice responsibility.

Backend Lead and Frontend Lead are craft communities of practice — raising the bar and spreading AI ways of working within a discipline. They are not titles, reporting lines, or a step back toward discipline-siloed squads; full-stack delivery in the squads is unchanged. Hats sit alongside the reporting lines, not inside them. On the org charts above, the Delivery Lead hat shows inside each squad; the Backend and Frontend Lead hats are cross-cutting and don’t appear as boxes.