Prepare for and practice interview questions from Lightmatter.

Lightmatter Interview Questions

Lightmatter Interview Guides

<p>Let’s say we have a table with an <code>id</code> and <code>name</code> fields. The table holds over 100 million rows and we want to sample a random row in the table without throttling the database.</p>

<p>Write a query to randomly sample a row from this table.</p>

<p><strong>Input:</strong></p>

<p><code>big_table</code> table</p>

<table>
<thead>
<tr>
<th>Columns</th>
<th>Type</th>
</tr>
</thead>

<tbody>
<tr>
<td><code>id</code></td>
<td>INTEGER</td>
</tr>

<tr>
<td><code>name</code></td>
<td>VARCHAR</td>
</tr>
</tbody>
</table>


Write a query to randomly sample a row from a big table.

Random SQL Sample

<p>You are testing hundreds of hypotheses with many <em>t</em>-tests. What considerations should be made?</p>


<p>What is a key disadvantage of the F-test when compared to multiple t-tests?</p>

What is a key disadvantage of the F-test when compared to multiple t-tests?

Hundreds of Hypotheses

You are testing hundreds of hypotheses with many t-tests. What considerations should be made?

<p>Let’s say you work for a social media company that has just done a launch in a new city. Looking at weekly metrics, you see a slow decrease in the average number of comments per user from January to March in this city.</p>

<p>The company has been consistently growing new users in the city from January to March.</p>

<p>What are some reasons why the average number of comments per user would be decreasing and what metrics would you look into?</p>


<p>What metric could be used to measure if active users are still engaging on the platform despite an overall decrease in the average number of comments per user?</p>

What metric could be used to measure if active users are still engaging on the platform despite an overall decrease in the average number of comments per user?

Decreasing Comments

How would you investigate a decline in the average number of comments per user?

Lightmatter Salaries by Position

<p>Lightmatter builds chips for artificial intelligence computing. Our architecture leverages unique properties of light to enable fast and efficient inference and training engines. If you're a collaborative engineer or scientist who has a passion for innovation, solving challenging technical problems and doing impactful work like building the world's first optical computers, consider joining the team at Lightmatter!
We are looking for talented software engineers to help us build the next generation of AI processors and large-scale systems. Lightmatter’s unique technology has the potential to alter the architecture of large-scale computers. In this role, you will be responsible for simulations and analysis of design concepts and planned hardware at multiple levels of scale and detail that will play a key role in the hardware-software codesign of future systems.
Responsibilities Design, development, and maintenance of functional and performance models for design concepts and planned hardware, at both the subsystem and system levels
Participate in the co-design process by working closely with both hardware and software teams by providing initial pathfinding analysis, developing early analytical models, and more detailed event-based simulations, improving fidelity as designs progress
Collaborate with machine learning and compiler teams to construct and evaluate the performance of machine learning workloads
Contribute to successful execution for planned hardware by building detailed cycle approximate performance and functional models that help drive microarchitectural design and validation
Minimum Qualifications BS or higher in computer/software engineering, electrical engineering, or related field
8+ years of industry experience in hardware modeling, system simulation, computer architecture, or related fields
Proficient with C++ and Python
Preferred Qualifications Familiarity with machine inference and training learning workloads
Experience with modeling and analysis of machine learning accelerator architectures and/or large-scale distributed systems
Proficient developing in a Linux-based environment
Benefits Comprehensive Health Care Plan (Medical, Dental & Vision)
401k matching
Life Insurance (Basic, Voluntary & AD&D)
Generous Time Off (Vacation, Sick & Public Holidays)
Paid Family Leave
Short Term & Long Term Disability
Training & Development
Flexible, hybrid workplace model
Stock Option Plan
We offer competitive compensation. The base salary range for this role, inclusive of all US locations, is $175,000-$205,000. Your base salary will be determined based on location, experience, educational background, and market data.
Lightmatter recruits, employs, trains, compensates and promotes regardless of race, religion, color, national origin, sex, disability, age, veteran status, and other protected status as required by applicable law.

#J-18808-Ljbffr</p>

Lightmatter Interview Questions

Lightmatter Interview Guides

Lightmatter Interview Questions

Lightmatter Salaries by Position

Lightmatter Opening Jobs