Lead Full Stack Developer

Saatchi & Saatchi is seeking a Lead Full Stack Developer for an innovative AI platform initiative.
You have 8 years building production software systems and at least a few years leading or anchoring a team technically. You are a hands-on builder and you hold the architectural picture of a multi-tier platform React frontend Spring Boot backend FastAPI agentic services agent SDKs on top of LLM providers. You are equally comfortable reviewing a database migration debugging a prod incident mentoring a senior engineer or sitting in a client architecture conversation. You thrive at the intersection of architecture engineering and program reality.

Responsibilities

• Own the technical direction across the platforms tiers frontend backend agentic/AI services data and integrations and hold the shared mental model of how the system actually fits together.
• Pair closely with the Senior Technical PM and Program Director to translate product intent into a credible technical plan and to surface what is genuinely hard vs. what is just unfamiliar.
• Lead architecture and design reviews write the deciding ADR when needed and keep a small set of vendor-neutral patterns the team can lean on instead of a sprawl of frameworks.
• Stay hands-on in the code pick up meaningful slices of work especially across tier boundaries (e.g. backend agentic frontend auth/RBAC infra-aware app changes).
• Be a first-class code reviewer across the stack: you set the bar for clarity testability security and operability and you raise the teams bar by reviewing thoughtfully.
• Mentor mid-level and senior engineers; coach them through technical decisions on-call experiences and difficult code reviews.
• Partner with the Platform Engineer on production reliability capacity scaling observability and incident response and own application-side reliability concerns.
• Drive integration architecture with internal and external systems using API-first and event-driven patterns; ensure identity authorization data protection and auditability are built in not bolted on.
• Champion the LLM/agent layer agent orchestration tool/plugin design prompt and evaluation loops provider abstraction (e.g. Vertex AI Claude on Vertex OpenAI) and keep us out of vendor lock-in we cannot pay for.
• Build redundancy on yourself pair document rotate ownership and ensure no critical system has exactly one person who understands it.

• 8 years in software engineering with meaningful time as a hands-on lead staff engineer or solutions architect on production systems.
• Proven experience designing and delivering complex multi-service platforms not just one service or one tier.
• Strong backend depth in at least one modern stack (Java/Spring Boot Python/FastAPI Node ); able to ramp on the others.
• Solid frontend literacy comfortable reading and reviewing modern React/TypeScript code and reasoning about state management auth and performance.
• Strong cloud architecture background preferably GCP (we run primarily on GKE); willing to deepen wherever the platform takes us.
• Deep understanding of API design integration patterns distributed systems and the failure modes that come with them.
• Experience with containerization Kubernetes and modern CI/CD; you do not need to be a DevOps specialist but you must operate well in that world.
• Real production experience with AI / LLM systems agents RAG evaluation tool integration or a strong demonstrable plan for getting there.
• Comfortable working within Agile delivery models (Scrum Kanban or whatever variant actually ships).
• Excellent communication: you can explain a complex architecture to a non-technical executive and disagree with a senior engineer respectfully and with evidence.

Required Soft Skills

• Hands-on bias you reach for the code the logs and the diagram before you reach for the meeting invite.
• Calm decisive judgment when there is no obviously right answer.
• Strong written communication you can write a one-page architecture rationale that future-you will still understand.
• Generous mentorship instinct you make the people around you better on purpose.
• Comfortable with ambiguity and willing to make reversible decisions quickly while flagging the irreversible ones for broader input.
• Pragmatic about technology choices you optimize for the teams ability to operate the system not for personal stack preferences.
• Honest about what you do and do not know; willing to say Ill find out and then actually find out.

Nice to Have

• Prior experience working inside Publicis Groupe or another large holding-company agency network.
• Production experience with Google ADK LangGraph LlamaIndex or comparable agent frameworks.
• Experience with event-driven architectures domain-driven design and contract-first integration patterns.
• Background in regulated or privacy-sensitive environments (identity healthcare financial marketing-compliance).
• Experience supporting multiple products or clients on a shared platform (multi-tenant multi-brand white-label).
• Comfort with Terraform Kustomize or other IaC tooling at a can read and improve level.
• Track record contributing to internal developer experience patterns scaffolds golden paths.

Location & Eligibility: Candidates must be based in Canada with valid Canadian work authorization of at least 12 months.

Hybrid Work: This role is remote. If you are GTA-based the team meets once a month at our Toronto office (111 Queen St. E Suite 200 Toronto ON M5C 1S2).

Time Off:

- Up to 3 weeks vacation with additional paid closure between Christmas and New Years

- Extended long weekends for provincial holidays we give you both the Monday and Friday so you get a full 4-day break

- 10 personal days per year

Flexibility & Global Mobility: After completing one year work remotely for up to 6 weeks per year from any of our 50 global offices through our Work Your World program.

Benefits: Comprehensive group coverage including:

- Medical dental and vision care

- Psychological and paramedical services

- Disability insurance

- Fertility support and gender-affirming care

- Dedicated internal guidance programs for employees navigating cancer fertility treatments or gender transition

Parental Leave Top up: A 100% salary top up program once approved for Employment Insurance for the first 6 weeks of your parental Leave.

Defined Contribution Pension Plan: Employees have the option to sign up to voluntarily contribute to a DCPP where Saatchi will match the employee contributions up to 5% after completing one year.

Gym Membership: Corporate Membership rates at Good Life Fitness

Free access to a financial planner & more

Compensation: The salary range for this position is $130000$150000 per year based on experience skills and relevant certifications. We believe in pay transparency and are committed to offering competitive market-aligned compensation.

We use artificial intelligence (AI) tools to support parts of our hiring process such as reviewing applications or analyzing resumes. These tools assist our recruitment team but never replace human decision-making. We believe in a human-first approach where your experience and potential are recognized by people.

Saatchi & Saatchi is committed to building a diverse workforce representative of our community. We encourage and are pleased to consider all qualified candidates without regard to race colour citizenship religion sex marital / family status sexual orientation gender identity aboriginal status age disability or persons who may require an accommodation to apply. If you require a specific accommodation please contact Human Resources at or by email at