Introduction
This post is for Day 21 of the Merpay & Mercoin Advent Calendar 2025\.
Hi, I’m ntk1000, an Engineering Manager for the KYC and Partner Platform teams at Merpay. Six months ago, we introduced our company-wide initiative to improve Developer Experience (DevEx) across Mercari Group. We designed a quarterly improvement cycle, achieved 100% participation from engineers and EMs, and identified structural challenges in areas like Deep Work (uninterrupted time for focus) and cross-team Collaboration.
During the first six months (FY25 Q4 → FY26 Q1), our overall developer experience metrics showed little change. While some teams demonstrated significant improvements, many remained stagnant. After reassessing our approach based on this reality, the most recent quarter (FY26 Q2) saw substantial improvements across the organization, particularly in Deep Work. We achieved improvement levels typically considered annual targets within a single quarter, clearly demonstrating the effectiveness of our approach shift.
This article shares our nine-month journey, achievements, and efforts to scale DevEx improvements across the organization.
Scaling Improvements: From Teams to Organization-Wide
Phase 1 (FY25 Q4 → FY26 Q1): Localized Success and Overall Stagnation
The FY26 Q1 survey showed most organizations’ developer experience metrics remained flat. However, analyzing specific challenge areas and team-level data revealed successful improvement cases.
Analysis of Success Cases
For Deep Work specifically, we investigated teams that achieved significant improvements and found common patterns:
- Established clear policies to protect focus time
- Organized meetings, defined and implemented consolidation rules
- Set team-wide "No Meeting Time" blocks
- Regularly held engineer focus days—e.g., monthly two-day periods completely free of meetings
- Automated routine tasks using AI tools
The common thread in these initiatives is policy-based improvements supported by team-wide commitment. Rather than individual efforts, they were implemented as structural changes agreed upon by entire teams, with policy-based approaches enabling rapid deployment and adoption.
However, team-level implementation resulted in inconsistent improvement responses and prevented natural horizontal deployment of success patterns.
Phase 2 (FY26 Q1 → FY26 Q2): Fusion of Bottom-up and Top-down
Recognizing the limitations of team-level improvements alone, we built a system to simultaneously activate both bottom-up and top-down approaches. The two-layered improvement cycle can be summarized as follows:
Bottom-up:
Team-level improvement cycle established from FY25 Q4:
- Actors: Individual Contributors (ICs) and Engineering Managers (EMs)
- Characteristics:
- Agile and responsive to team-specific challenges
- High success rate in areas teams can control and respond to quickly (Deep Work, Documentation, Code Maintainability, etc.)
Top-down:
Organization-level improvement cycle fully established from FY26 Q2:
- Actors: VPoE, Directors, Managers of Managers (MoMs)
- Purpose:
- Address structural challenges difficult for individual teams to solve
- Cross-organizational policy decisions and resource allocation
- Standardization and horizontal deployment of success patterns
Specific Implementation Example
Within the Fintech organization (which includes Merpay/Mercoin), requests for Deep Work improvement remained consistently high while scores remained low. Under VPoE leadership, Deep Work improvement was designated as an organizational priority, with the following initiatives:
- Visualization of Deep Work-related metrics across Fintech organizations (Deep Work scores, proportion of meeting-heavy days and interruptions)
- Horizontal deployment and localization of Deep Work improvement examples
- Review and consolidation of regular meetings within the organization
- Sharing and standardization of success cases across teams
- More detailed challenge analysis using additional surveys
- Support for EMs in executing improvements
- Progress tracking
- Reporting to executive leadership, sharing initiatives with non-engineering organizations
Organization-wide averages that hadn’t changed through individual team efforts alone achieved approximately 16% improvement in a single quarter by combining VPoE-led top-down initiatives with EM/IC-led bottom-up execution. These results have been reported to executive meetings and are scheduled to be shared at company-wide gatherings.
The clear policies protecting focus time that proved effective for Deep Work improvement are considered applicable to non-engineering organizations as well. We expect this will lead to company-wide Deep Work improvements.
Additionally, since this round primarily involved policy-based improvements with rapid deployment and adoption, effects were more easily realized across the organization. Going forward, we need to address not only easily tackled short-term initiatives but also more challenging issues requiring long-term responses.
Learnings from DX
In redesigning our approach, insights from a presentation by DX (the company providing our DevEx platform) proved valuable. We’d like to briefly share these learnings.
Initiatives Need Structure
The presentation emphasized that many DevEx improvements fail not due to lack of team interest, but due to lack of proper structure. Three components were identified as essential for success:
1: Build the Business Case
Translate developer pain into business outcomes, not just explain the pain:
- Connect to organizational KPIs: Time loss, cost, quality, retention
- Quantify impact at scale: 20 minutes lost per build per developer × 700 engineers \= significant cost
- Show value unlocked: Not just removing pain, but what becomes possible (faster features, higher reliability, better recovery)
2: Structure the Initiative Properly
- Timebox for 6-12 months minimum: Real change takes time. Sprints produce quick wins but don’t form habits.
- Set natural checkpoints: Baseline → midpoint → end measurement
- Enable team mobilization: Give time for communication, planning, and embedding practices
3: Define Appropriate Metrics
- Northstar KPI: Productivity, satisfaction, quality, retention
- Leading indicators: What teams can directly influence (e.g., build time, review time)
- Guardrails: Prevent gaming (e.g., PR count alone can be artificially inflated)
Three Essential Roles
All successful initiatives require:
- Executive Sponsor: Provides top-down leadership and business alignment (e.g., VPoE decision-making)
- Champion: Frames problems with data and provides tactical guidance (e.g., Directors and MoMs understanding organizational data and determining direction)
- Manager: Allocates time and translates initiatives into team-level actions (e.g., EMs and ICs improving teams)
Without any of these roles, initiatives stagnate.
Sustainability Through Visibility
To prevent initiatives from stalling midway, the following mechanisms are recommended:
- Visualization: Dashboards showing progress/lack of progress
- Operational reviews: Regular meetings with challenges/actions/outcomes
- Clear leadership: Accountability for progress, business alignment
Ongoing Challenges
Some challenges remain unresolved, and we continue working on them.
Difficulty of Horizontal Deployment
Success patterns don’t spread automatically. Mercari Group particularly has diverse product phases and organization sizes, so approaches for mature large organizations may not apply to small organizations in startup phases.
Current efforts: Rather than simply collecting success cases, we’re organizing knowledge by including information like organization size and product phase, enabling each organization to autonomously identify applicable actions.
Measuring Long-term Impact
While we can measure survey scores and immediate metrics (meeting time, interruption frequency), connecting DevEx improvements to business outcomes (delivery speed, quality, retention) remains difficult.
Current efforts: We’re analyzing correlations between DX score improvements, various survey results, and quantitative data. No definitive conclusions yet.
Multi-quarter Continuity
While high participation rates continue, we’re seeing signs of survey fatigue and frustration with issues not improving.
Current efforts: We continue adjusting DX surveys to prevent bloat and holding internal DX-related events to regularly communicate significance.
Summary
Nine months ago when we started this initiative, we achieved strong engagement, identified structural challenges, and created action plans.
Currently, we’re at the stage of transforming initial momentum into sustained organizational change. We’ve moved from a situation with wide variance—some teams achieving significant results while others faced challenges—to being able to drive cross-organizational improvements.
Elements needed to scale DevEx improvement organization-wide:
- Structural support (improvement systems, role clarity)
- Cultural commitment (leadership from multiple directions, regular visibility)
- Practical frameworks (deployment of success cases teams can adapt)
We must continue to remember that improvement scores are indicators, not objectives. More importantly, we must maximize business outcomes by ensuring teams acquire these capabilities:
- Identify friction in daily work
- Clearly express issues to leadership
- Take collective action for improvement
- Measure and reflect on results
DevEx as Continuous Practice
Continuous practice is essential to quickly identify and address challenges as products evolve, organization size and structure changes, and AI transforms development practices.
The goal is not achieving perfect scores, but building organizational capability to continuously sense and respond to developer experience issues, thereby increasing productivity.
While Phase 1 saw flat organization-wide overall developer experience metrics, Phase 2 achieved significant improvements. We’ll continue improving this initiative itself to ensure this change becomes an ongoing improvement process rather than temporary.
Tomorrow’s article will be by @taki. Look forward to it!
