Tell us about what you learnt from a major failure at work.

Question

Anonymous · Accepted Answer

I was the lead engineer on a project to enhance our event-driven messaging
system. The system processes real-time messages and archives them into S3
buckets. These archived messages are then ingested by another team into
Snowflake, which serves as the backbone for various downstream pipelines and
analytics reporting.
We recently implemented an update to the S3 archiver to write data to
multi-region buckets based on the message-producing country. This was a crucial
update aimed at improving data redundancy and compliance with regional data
regulations.
While the deployment of the multi-region S3 buckets was successful, I overlooked
the need to inform the Snowflake team about the changes. As a result, their
ingestor continued to point to the old S3 buckets, causing Snowflake to go out
of sync. This led to a cascading failure in all downstream processes, including
inaccurate analytics reporting and failed data pipelines.
The mistake led to significant disruptions in downstream processes, with
incorrect reports being generated for critical business decisions. Once I
realized the oversight, I immediately coordinated with the Snowflake team to
update their ingestor to point to the correct S3 buckets. After the fix, I took
steps to ensure better communication and coordination between teams, including
setting up a process for notifying all stakeholders of changes that could impact
their systems. This experience reinforced the importance of cross-team
communication, especially in environments where multiple systems are
interdependent.
This scenario effectively demonstrates your ability to own up to a mistake,
address it quickly, and learn from the experience. It also highlights the
complexity of the systems you're working with and your role in leading such
projects. By discussing how you implemented better communication protocols
afterward, you show your growth as a senior engineer who is proactive in
preventing similar issues in the future

Anonymous · Answer

I was tasked with deploying a new version of our application to production.
During the deployment, I mistakenly missed a crucial configuration, which caused
a part of the application to malfunction. My task was to ensure a smooth
deployment with minimal disruption to the users. Once the issue was identified,
I immediately halted the deployment and rolled back to the previous version. I
then thoroughly reviewed the deployment process and noticed the missing
configuration file. I added the file and conducted a comprehensive test in a
staging environment before redeploying the application. The redeployment was
successful, and the application functioned as expected. The user impact was
minimal, and the system was back online shortly after the correction. To prevent
similar issues, I now maintain a checklist for deployment that includes
verifying all configuration files and dependencies. I also conduct
pre-deployment checks in a staging environment to catch potential problems
early.

Anonymous · Answer

I was reviewing product test results with the customer to get sign-off on
proceeding to the next phase of building and testing. The results that were
being shown were consistent with previous results that we had reviewed with the
customer in earlier phases. Upon finishing our review, there were several
engineers on the customer side that were not OK with the results and wanted us
to make a change in order to better fit in with the specifications. I stated
that these results and measurements were agreed upon in earlier reviews and and
making a change this late in the process could push the timeline back to where
we may not be able to meet production schedule. At this point the customer
engineer's asked if I had the signed documents to showcase that this is what had
been agreed to. I only had verbal and email communications with agreements but
nothing with a signature. Since there was no signature, my team was forced to
provide a fix under a short time constraint. As the project engineer/manager it
is my job to ensure that proper documentation is had and follow to avoid
situations like these. I took this as a learned lesson to never get too
comfortable with the customer and the key importance of documentation. I have
since, made certain that proper documentation is there for all stages of the
project that I work on.

Anonymous · Answer

When buildling the next generation instance, during the planning phase I budget
the amount of servers we will launch the product with. Given each server cost
was over 2 million dollar I biased to towards frugality and provided a bare
minimum number of server we could launch with. But what I completely missed was
during the developement some servers will end up in bad state and the
engineering team will short of servers to test the software and firmware getting
built which made meeting the project timeline riskly and heavily dependent on
delivery schedules of servers and them staying healthy. This quickly became a
bottleneck that I realized. I quickly put togther a plan to request adittional
server and provide a detailed breakdown on where and how these would be used
during and after developement. Synced with the hardware and ODM team and
executives to get a approval and ordered the parts to get the servers and racks
build at ODM.

Tell us about what you learnt from a major failure at work.

Practice this question with AI

Go Premium

Practice More Questions

Community Answers

Unlock Community Insights

Unlock Community Insights

Unlock Community Insights

Unlock Community Insights

Everything You Need to Ace DS Interviews