Senior Software Engineer

Senior Full Stack Software Engineer

Location: Onsite in Toronto, ON

About Sales Jack

Sales Jack is a fast-growing, profitable sales software platform (CRM, Prospecting Service) purpose-built for independent businesses in the construction supply industry. Our team and customers are spread across the US and Canada. Our mission: build tools that solve real problems for our customers and transform industry workflows.

Your Role

As a Senior Full Stack Software Engineer at Sales Jack, you'll be one of the senior technical hires on the team - owning major product surfaces end-to-end. That means more than writing code: you'll talk to customers, scope what to build, make the product calls, and ship it. We don't have a PM layer between engineering and customers; the engineers closest to the problem own the solution.

You'll partner directly with the founders and lead engineers to set architectural direction and raise the engineering bar while also bringing real product taste to the work. This is a hands‑on role: writing production code daily, making the calls on what gets built and how it scales, and sweating the details of how it feels to use.

We highly value a startup mentality. Strong opinions held loosely, fast iteration, and a bias toward shipping over deliberating.

What You'll Do:

• Own entire product features from "this is a problem worth solving" to "this is live in customers' hands" — scoping, designing, building, shipping, iterating

• Talk to customers directly: discovery calls, support tickets, ride‑alongs with sales reps in lumberyards. Use what you learn to make better product decisions

• Make the architectural calls on new systems — data model, API surface, frontend composition — and document the reasoning so the team can build on it

• Build across our Node.js stack:
  Next.js on the frontend, Node services on the backend, BullMQ for background jobs and workflows, Postgre
  
  SQL as the system of record

• Design and operate authentication, authorization, and multi‑tenant RBAC systems that hold up under real customer load

• Build durable, queue‑driven automation with BullMQ — orchestrating long‑running processes, retries, and integrations against external ERPs and third‑party APIs

• Set technical standards (testing, code review, CI/CD, observability) and raise the bar for everyone around you, including the founders

• Mentor engineers and lead design reviews

What We're Looking For:

Engineering

• 8–10 years of full stack engineering experience, including time spent owning systems in production at meaningful scale

• Deep expertise in React and Next.js, with a strong point of view on component architecture, state management, and performance

• Strong backend chops in Node.js — you've designed and operated services, not just built features inside them

• Advanced Postgre
  
  SQL — schema design, query optimization, migrations under load, multi‑tenant patterns

• Production experience with auth/RBAC systems, especially in multi‑tenant B2B contexts

• Hands‑on experience with BullMQ or comparable queue/job systems (Sidekiq, Rabbit
  
  MQ, SQS, Temporal) — and a clear sense of when to reach for them vs. simpler patterns

Product

• A real product brain. You can be handed a fuzzy customer problem and come back with a scoped, shippable plan — not a Jira ticket asking for specs

• Strong product taste. You push back on bad designs, come up with better ones, and have opinions about what "good" looks like in B2B software

• Customer instinct. You actually want to talk to users, watch them work, and let what you learn shape the product. You don't need to be shielded from messy customer feedback

• Ability to make tradeoff calls — what to cut, what to defer, what to over‑invest in — without needing a PM to break the tie

Why Join Us:

• Profitable and growing

• Fast iteration, direct collaboration with founders, and unfiltered customer feedback

• Highly competitive salary and comprehensive health benefits

Hiring Process

• Initial call with our founding engineer to discuss your background and introduce Sales Jack (~30 mins)

• Technical Exercise:
  Product Design, Live coding and problem‑solving session (~2.5 hours, might be 2 separate sessions)

• Product and culture call with one of our founders (~30 mins)

• Offer