Scaling AI-first software delivery at a leading Canadian fintech

Wealthsimple is Canada's fastest-growing fintech company. Managing over $100 billion in assets for 3 million clients, the company has built its reputation on disruptive innovation, offering services like commission-free and 24/5 trading.

To maintain momentum and achieve greater agility, Wealthsimple aimed to make AI a core part of how it builds and delivers software. While early experiments showed promise, the company recognized that unlocking its full value required a structured framework for adoption. Addressing consistency and integration challenges across engineering teams was essential to scaling AI beyond isolated successes.

Partnering with Thoughtworks, Wealthsimple launched a targeted initiative to build the foundation for an AI-native engineering organization. In a matter of weeks, AI was no longer a tool on the side, but the new standard for delivery.

The limits of early AI gains

Wealthsimple’s journey to building an AI-native engineering organization revealed the complexities of scaling AI across teams.

While initial AI adoption led to a roughly 20% productivity boost, these gains quickly plateaued. Although some engineers saw strong results, most felt they lacked a clear methodology for successfully applying AI to complex, day-to-day work. As a result, adoption progressed at uneven speeds across the organization.

Part of the challenge stemmed from the nondeterministic nature of LLMs themselves. Without structured guidance and well-defined inputs, the quality and reliability of outputs varied. Project requirements were also often vague, and when that ambiguity reached the AI, it led to inconsistent or low-quality code generation.

If left unaddressed, these issues risked slowing progress and limiting the company’s broader AI ambitions.

Rewiring delivery: The AI-first transformation framework

Going "AI-native" isn't just about giving developers access to large language models (LLMs); it requires a fundamental shift in how teams build and deliver software. 

Scaling that shift across Wealthsimple's ~550-person R&D organization — including engineers, designers and managers — demanded a structured, cross-functional approach.

To achieve this, Thoughtworks and Wealthsimple implemented an AI-first transformation framework. Rather than focusing purely on the tech, we focused on AI literacy and coaching to address gaps in adoption.

Here’s how we reshaped the software development lifecycle during the engagement:
 

• Reinforcing spec-driven development: We introduced spec-driven development to tightly align requirements with the AI's actual capabilities.

   

• Building an AI-first playbook: We developed a comprehensive playbook that equips engineers with core building blocks, actionable strategies for self-learning, and advanced context and prompt engineering techniques.

   

• Establishing a coaching network: We deployed a coaching network to actively upskill engineers in AI literacy, and introduced structured experimentation and iterative learning cycles so teams could continuously improve.

   

• Creating a change management process: We established a structured process to reinforce AI-first collaboration practices. This included higher-quality requirements with low ambiguity and clear acceptance criteria across stories, tasks, and epics; adoption of stacked PRs to reduce blockers; cross-team plan alignment; and integration of AI self-correction loops throughout every stage of the software development process.

The results

By combining cutting-edge LLMs with deep cultural coaching, the 6-week pilot program successfully tested and validated these AI-first delivery strategies. The subsequent 4-week rollout delivered measurable business impact:

What's next for Wealthsimple?

The initial rollout proved that true engineering transformation requires equal parts technological tooling and human literacy. 

With near-universal adoption now established, the program is advancing into the next frontier of AI-first software delivery, expanding to include capabilities like custom workflows, swarm and team design, self-correction loops, methods to manage context efficiently and agentic network security.

With this foundation in place, Wealthsimple is positioned to pursue more ambitious projects, bring new services to market faster and extend its leadership in Canada’s fintech market.